The present invention relates to a method and system for analyzing hydrocarbon containing oils. In particular, the present invention relates to the chromatographic analysis of hydrocarbon containing oils to provide quantification of seven classes of compounds (saturates, 1-4+ ring aromatics, sulfides, and is polars).
Compositional analysis of heavy petroleum streams is essential in order to improve efficiency of refinery operations. However, these streams are too complex to be analyzed as such, for detailed compositional information, even with the most modern analytical techniques/instruments. It is, therefore, essential to fractionate them into sub-groups of different classes of compounds so that the detail/extensive molecular compositional analyses can be performed using characterizing tools, e.g. high resolution mass spectroscopy. Preparative liquid chromatography (LC) has been used very extensively to fractionate heavy streams in terms of mainly three classes of compounds, namely ‘saturates’ (consist of n-paraffins, iso-paraffins, and naphthenes), ‘aromatics’ (consists of aromatic-hydrocarbons, aromatic-thiophenes, and some sulfides), and ‘polars’ (consists of heteroatom containing complex organic compounds). Additionally, ‘aromatics’ are further fractionated, using preparative liquid chromatography, mostly into four classes of aromatic compounds based upon number of aromatic rings such as one-, two-, three-, and four+-rings. Although these preparative liquid chromatographic approaches provide relatively pure fractions and the weight percent data, the LC separations are very laborious and time consuming and hence costly. Additionally, these separations are not very environmental friendly because they use large volume of organic solvents which must be evaporated in order to get pure fractions. On many occasions, particularly for R&D projects only weight percent data for various fractions are needed.
The present invention provides quantitation of seven classes of compounds (saturates, 1-4+ ring aromatics, sulfides, and polars) present in petroleum streams boiling from 550-1050° F. Operating the present invention in the preparative mode will allow us to load and collect multi-milligram amounts of material. In the present invention, all seven fractions are produced in a single run, whereas the most commonly used preparative liquid chromatographic separations requires two or more large scale separations to generate similar fractions. The present invention uses 100 times less solvent. The present invention protocol provides a quicker and cheaper alternative to most commonly used preparative liquid chromatographic separations and is flexible enough to target many refining and chemicals problems.